What is it?

Gamekeeper's thumb is a sprain of the ulnar collateral ligament of the thumb. The ulnar collateral ligament holds the proximal phalanx of the thumb to the metacarpal. Loss of function of the ligament causes instability to the thumb, so the patient has difficulty pinching which is needed in catching a ball or grasping a racket.

The name originates from the gamekeepers of old, who does so much skinning of rabbits that they suffer from a chronic sprain or loss of function of the ulnar collateral ligament of the thumb.

This is usually a result of an abduction injury to the thumb, as in basketball or football.

What does your doctor do about it?

X-rays are taken to rule out any fractures. A stress fracture is usually taken to check on the stability of the MP joint. If the joint opens up on stress X-rays, it usually indicates a complete rupture of the ulnar collateral ligament.

If the joint is stable, a thumb spica cast or brace for about 3 to 6 weeks is sufficient to allow healing of the ligament. If there has been complete rupture of the ligament, surgery is usually required to get a good result. The ruptured ligament tends to fold upon itself, and surgery is needed to sew the torn ends of the ligament together. Casting for 6 weeks after surgery is needed to ensure complete healing.